VEGETATIVE PROPAGATION OF LIME (Citrus aurantifolia Swingle) BY STEM CUTTINGS By Eiman Ahmed Swelih B.Sc. (Agric.) Honours (1999) University of Khartoum A thesis submitted to the University of Khartoum in partial fulfillment of the requirements for the degree of Master of Science in Agriculture Supervisor Prof. Abdelghafar El Hag Saeed Department of Horticulture Faculty of Agriculture University of Khartoum September - 2005 DEDICATION To my parents For lightening up the way To my sisters and brothers For the advice, consolation and fun To my nieces and nephews For a better future To my friends For wonderful memories to keep. To you all I dedicate this work X|ÅtÇ Acknowledgement Thanks are due forth and forward to Allah for easing my way towards knowledge and education. Iam grateful to my supervisor, Prof. Abdel-Gaffar El Haj Said who never hesitated to share his time, knowledge and effort with me. I would like to thank Dr. Ahmed Jamal, General Manager at the River Nile State’s, Ministry of Agriculture and Mr. Mohammed Ahmed Ibrahim, Manager of Horticultural Department at the same Ministry. Both persons exerted enough time and effort to my work easier, Iam ever grateful to them. Iam also thankful to the cheerful, faces of the family of School of Gardening and Nutrition Education Department, namely Mr. Abdallah Osman Nour Eldin, head of Department and Mr. Mohamed Majzoub, Mr. Suliman Selmi Suliman and Mr. Hasson Ahemd Alballa. Thanks are also due to Mr. Ali Yousif, Words will never describe how grateful Iam. Finally, Iam thankful for every other person who made this work asuccess, Dr. Mubarak Sir Elkhatim, Mr. Abdelnasir and Haitham and Mss. Lila Mohamed Khair. ABSTRACT Three experiments were conducted in this study to investigate the effect of seasons, girdling and sowing interval after girdling on rooting of lime stem cuttings. In the first experiment, 3 type of stem cuttings non girded, basal and Apical cuttings were taken from lime at summer season in different weeks interval (2, 4, 6, 8 and 10) weeks after girdling. All cuttings were planted in sand soil in plastic trays and then kept under plastic covered frames under lathe- house conditions. In this experiment, basal cuttings resulted in better values of percentage, number of roots, length of roots, number of new roots and growth vigor compared to non girdling and apical cuttings. Percentage of rooted cuttings and other parameters measured were influenced by time in which cuttings were taken. The highest percentage of rooted cuttings was obtained with cuttings taken 10 weeks after girdling and this may be attributed to the increase in quantity of carbohydrates and other rooting cofactors with the gradual increase in sowing interval after girdling. In the second experiment, the same procedures above in experiment (1) was repeated during autumn. The results showed that apical cuttings resulted in betters values of all parameters measured except number of new roots where basal cuttings gave better values of number of new roots. The highest values of root length, number of new roots and growth vigor were obtained from cuttings taken 2 weeks after girdling while cuttings taken 10 weeks after girdling gave better value of percentage of rooted cuttings. On the other hand the greatest number of roots was obtained with cuttings taken 6 weeks after girdling. In the third experiment which is the last one, the above procedures was repeated again during winter. The results revealed that apical cuttings resulted in better values of all parameters measured while cuttings taken 4 weeks after girdling gave better values of all parameters measured except percentage of rooted cuttings where cuttings taken 8 weeks after girdling gave the highest percentage of rooted cuttings. The highest percentage of rooted cuttings of lime was obtained in autumn (46.2%) followed by winter (44.2%) and then summer (4.7%). اﻟﺨﻼﺻﺔ أﺟﺮﻳﺖ ﺛﻼﺛﺔ ﺗﺠﺎرب ﻓﻲ هﺬﻩ اﻟﺪراﺳﺔ ﻟﻤﻌﺮﻓﺔ ﺗﺄﺛﻴﺮ ﻓﺼﻮل اﻟﺴﻨﺔ، اﻟﺘﺤﻠﻴﻖ وﻓﺘﺮة اﻟﺰراﻋﺔ ﺑﻌﺪ اﻟﺘﺤﻠﻴﻖ ﻋﻠﻰ إﻣﻜﺎﻧﻴﺔ اﻟﺘﺠﺬﻳﺮ ﻓﻲ اﻟﻌﻘﻞ اﻟﺴﺎﻗﻴﺔ ﻟﻠﻴﻤﻮن اﻟﺒﻠﺪي. ﻓﻲ اﻟﺘﺠﺮﺑﺔ اﻷوﻟﻲ ﺗﻢ ﺗﺠﻬﻴﺰ ﺛﻼﺛﺔ أﻧﻮاع ﻣﻦ اﻟﻌﻘﻞ اﻟﺴﺎﻗﻴﺔ ، ﻋﻘﻞ ﻏﻴﺮ ﻣﺤﻠﻘﺔ ، ﻋﻘﻞ ﻗﺮﻳﺒﺔ ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ ، ﻋﻘﻞ ﺑﻌﻴﺪة ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ ﻓﻲ ﻣﻮﺳﻢ اﻟﺼﻴﻒ وﺗﻤﺖ اﻟﺰراﻋﺔ ﺑﻌﺪ أﺳﺎﺑﻴﻊ ﻣﺨﺘﻠﻔﺔ (2 ، 4 ، 6 ، 8 و 10) أﺳﺎﺑﻴﻊ ﻣﻦ اﻟﺘﺤﻠﻴﻖ. ﺟﻤﻴﻊ اﻟﻌﻘﻞ زرﻋﺖ ﻓﻲ ﺗﺮﺑﺔ رﻣﻠﻴﺔ ﻓﻲ أوﻋﻴﺔ ﺑﻼﺳﺘﻴﻚ ﻣﻐﻄﺎة ﺑﻐﻄﺎء ﺑﻼﺳﺘﻴﻜﻲ ﺛﻢ وﺿﻌﺖ ﻓﻲ اﻟﻤﺸﺘﻞ. أﻇﻬﺮت ﻧﺘﺎﺋﺞ هﺬﻩ اﻟﺘﺠﺮﺑﺔ أن اﻟﻌﻘﻞ اﻟﻘﺮﻳﺒﺔ ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ أﻋﻄﺖ أﻋﻠﻰ اﻟﻘﻴﻢ ﻓﻲ ﻧﺴﺒﺔ اﻟﻨﺠﺎح ، ﻋﺪد اﻟﺠﺬور ، ﻃﻮل اﻟﺠﺬور ، ﻋﺪد اﻟﺠﺬور اﻟﺠﺪﻳﺪة، وﻗﻮة اﻟﻨﻤﻮ ﻣﻘﺎرﻧﺔ ﻣﻊ اﻟﻌﻘﻞ ﻏﻴﺮ اﻟﻤﺤﻠﻘﺔ واﻟﻌﻘﻞ اﻟﺒﻌﻴﺪة ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ. أﺛﺒﺘﺖ اﻟﺘﺠﺮﺑﺔ أن ﻧﺴﺒﺔ ﻧﺠﺎح اﻟﻌﻘﻞ وﺑﺎﻗﻲ اﻟﻘﺮاءات اﻟﺘﻲ أﺧﺬت ﺗﺘﺄﺛﺮ ﺑﺰﻣﻦ أﺧﺬ اﻟﻌﻘﻞ ﺣﻴﺚ أﻋﻄﺖ اﻟﻌﻘﻞ اﻟﺘﻲ أﺧﺬت ﺑﻌﺪ 10 أﺳﺎﺑﻴﻊ ﻣﻦ اﻟﺘﺤﻠﻴﻖ أﻋﻠﻰ ﻧﺴﺒﺔ ﻧﺠﺎح وهﺬا رﺑﻤﺎ ﻳﻌﺰى إﻟﻰ إزدﻳﺎد آﻤﻴﺔ اﻟﻜﺎرﺑﻮهﻴﺪرﻳﺘﺎت وﻋﻮاﻣﻞ اﻟﺘﺠﺬﻳﺮ اﻷﺧﺮى ﺑﺎﻹزدﻳﺎد اﻟﺘﺪرﻳﺠﻲ ﻓﻲ ﻓﺘﺮة اﻟﺰراﻋﺔ ﺑﻌﺪ اﻟﺘﺤﻠﻴﻖ. ﻓﻲ اﻟﺘﺠﺮﺑﺔ اﻟﺜﺎﻧﻴﺔ ﺗﻢ ﺗﻜﺮار ﻧﻔﺲ اﻟﺨﻄﻮات اﻟﺘﻲ اﺟﺮﻳﺖ ﻓﻲ اﻟﺘﺠﺮﺑﺔ اﻷوﻟﻲ ﻓﻲ ﻓﺼﻞ اﻟﺨﺮﻳﻒ. أﻇﻬﺮت اﻟﻨﺘﺎﺋﺞ أن اﻟﻌﻘﻞ اﻟﺒﻌﻴﺪة ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ أﻋﻄﺖ ﻗ ﻴ ﻤ ﺎً أﻋﻠﻰ ﻓﻲ آﻞ اﻟﻘﺮاءات اﻟﺘﻲ أﺧﺬت ﻣﺎﻋﺪا ﻋﺪد اﻟﺠﺬور اﻟﺠﺪﻳﺪة ﺣﻴﺚ أﻋﻄﺖ اﻟﻌﻘﻞ اﻟﻘﺮﻳﺒﺔ ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ ﻗ ﻴ ﻤ ﺎً أﻋﻠﻰ. أﻋﻄﺖ اﻟﻌﻘﻞ اﻟﺘﻲ أﺧﺬت ﺑﻌﺪ إﺳﺒﻮﻋﻴﻦ ﻣﻦ اﻟﺘﺤﻠﻴﻖ أﻓﻀﻞ اﻟﻨﺘﺎﺋﺞ ﻓﻲ ﻃﻮل اﻟﺠﺬور ، ﻋﺪد اﻟﺠﺬور اﻟﺠﺪﻳﺪة وﻗﻮة اﻟﻨﻤﻮ، ﺑﻴﻨﻤﺎ أﻋﻄﺖ اﻟﻌﻘﻞ اﻟﺘﻲ أﺧﺬت ﺑﻌﺪ 10 أﺳﺎﺑﻴﻊ ﻣﻦ اﻟﺘﺤﻠﻴﻖ أﻋﻠﻰ ﻧﺴﺒﺔ ﻧﺠﺎح واﻟﻌﻘﻞ اﻟﺘﻲ أﺧﺬت ﺑﻌﺪ 6 أﺳﺎﺑﻴﻊ ﻣﻦ اﻟﺘﺤﻠﻴﻖ أﻋﻄﺖ أﻓﻀﻞ اﻟﻘﻴﻢ ﻓﻲ ﻋﺪد اﻟﺠﺬور. ﻓﻲ اﻟﺘﺠﺮﺑﺔ اﻟﺜﺎﻟﺜﺔ واﻷﺧﻴﺮة ﺗﻢ ﺗﻜﺮار ﻧﻔﺲ اﻟﺨﻄﻮات أﻋﻼﻩ ﻓﻲ ﻓﺼﻞ اﻟﺸﺘﺎء أﻇﻬﺮت اﻟﻨﺘﺎﺋﺞ أن اﻟﻌﻘﻞ اﻟﺒﻌﻴﺪة ﻣﻦ ﻣﻨﻄﻘﺔ اﻟﺘﺤﻠﻴﻖ أﻋﻄﺖ أﻓﻀﻞ اﻟﻨﺘﺎﺋﺞ ﻓﻲ آﻞ اﻟﻘﺮاءات اﻟﺘﻲ أﺧﺬت ﺑﻴﻨﻤﺎ أﻋﻄﺖ اﻟﻌﻘﻞ اﻟﺘﻲ أﺧﺬت ﺑﻌﺪ 4 أﺳﺎﺑﻴﻊ ﻣﻦ اﻟﺘﺤﻠﻴﻖ أﻋﻠﻰ اﻟﻘﻴﻢ ﻓﻲ آﻞ اﻟﻘﺮاءات اﻟﻤﺄﺧﻮذة ﻣﺎﻋﺪا ﻧﺴﺒﺔ اﻟﻨﺠﺎح ﺣﻴﺚ أﻋﻄﺖ اﻟﻌﻘﻞ اﻟﺘﻲ أﺧﺬت ﺑﻌﺪ 8 أﺳﺎﺑﻴﻊ ﻣﻦ اﻟﺘﺤﻠﻴﻖ أﻋﻠﻰ ﻧﺴﺒﺔ ﻧﺠﺎح. أﻋﻠﻰ ﻧﺴﺒﺔ ﻧﺠﺎح ﻟﻌﻘﻞ اﻟﻠﻴﻤﻮن اﻟﺒﻠﺪي أﺧﺬت ﻓﻲ ﻓﺼﻞ اﻟﺨﺮﻳﻒ (46.2%) ﻳﻠﻴﻪ ﻓﺼﻞ اﻟﺸﺘﺎء (44.2%) ﺛﻢ ﻓﺼﻞ اﻟﺼﻴﻒ (%4.7). LIST OF CONTENTS Page Dedication………………………………………………………………………………….. i Acknowledgement ………………………….…………………………………………… ii Abstract ……………………………………………………………………………………… iii Arabic Abstract …………………………...……………………………………………… v List of Contents ………………………..………………………………………………… vii List of Tables………………………………….…………………………………………… xii List of Figures …………………………..………………………………………………… xiii 1. Introduction…………………………………….…………….……………………… 1 2. LITERATURE REVIEW…….………………………………………………… 7 2.1. Cultural practices.………………………………………….……………………… 8 2.1.1. Planting.…………………………………………………………..………………… 8 2.1.2. Fertilization.……………………………………………..………………………… 10 2.1.3. Irrigation.…………………………………………………………………………… 11 2.1.4. Pruning.……………………………………………………………………………… 11 2.1.5. Harvesting.……………………………………….………………………………… 12 2.1.6. Propagation.…………………………………….………………………………… 13 2.1.6.1. Seed propagation of citrus trees.……………………………………… 14 2.1.6.2. Vegetative propagation of citrus trees.……………………………… 16 2.1.6.2.1. Propagation on a root stock.…………………………………..……… 18 2.1.6.2.2. Own – rooted trees.…………………………….………………………… 21 3. MATERIALS AND METHODS.…………………………………………… 30 3.1 Experimentation.……………………………………………….…………………… 30 3.2 Plant materials.……………………………………………………………………… 30 3.3 Experiment No. 1. Summer Experiment.…………………….…………… 30 3.4 Experiment No. 2. Autumn Experiment.………………………………… 31 3.5 Experiment No. 3. Winter Experiment.…………………………………… 31 3.6 Planting media.………………………….……………..…………………………… 31 3.7 Incubation conditions.………………..…………………………………………… 32 3.8. Parameters measured.……………………………….…………………………… 32 3.9 Experimental design and data analysis.………………………………… 33 4. RESULTS.………………………………………………………..…………………… 34 4.1. Summer experiments……………………………………………..……………… 4.1.1 Effect of girdling and sowing interval on percentage of rooted 34 lime stem cuttings…………….…………………………………………………..……… 4.1.2. Effect of girdling and sowing interval on number of roots of lime stem cuttings…………………………………………………..…………………… 37 4.1.3. Effect of girdling and sowing interval on length of roots of lime stem cuttings………………………….…………………………………………… 40 4.1.4. Effect of girdling and sowing interval on number of new roots of lime stem cuttings…………………………………………………………… 40 4.1.5. Effect of girdling and sowing interval on growth vigor of lime stem cuttings………………………………………..……………………………… 45 4.2. Autumn experiments……………………………..……………………………… 48 4.2.1. Effect of girdling and sowing interval on percentage of rooted lime stem cuttings………………………………….………………………… 48 4.2.2. Effect of girdling and sowing interval on number of roots of lime stem cuttings………………………………………..……………………………… 48 4.2.3. Effect of girdling and sowing interval on length of roots of lime stem cuttings………………………………………...……………………………… 50 4.2.4. Effect of girdling and sowing interval on number of new roots of lime stem cuttings…………………………………………………………… 53 4.2.5. Effect of girdling and sowing interval on growth vigor of lime stem cuttings………………………………………...……………………………… 53 4.3. Winter experiments………………………………..……………………………… 57 4.3.1. Effect of girdling and sowing interval on percentage of rooted lime stem cuttings…………………………..………………………………… 57 4.3.2. Effect of girdling and sowing interval on number of roots of lime stem cuttings……………………...………………………………………………… 57 4.3.3. Effect of girdling and sowing interval on length of roots of lime stem cuttings……………………………..………………………………………… 59 4.3.4. Effect of girdling and sowing interval on number of new roots of lime stem cuttings…………………………….……………………………… 62 4.3.5. Effect of girdling and sowing interval on growth vigor of lime stem cuttings………………………………….…………………………………… 62 4.4. Effect of seasons, girdling and sowing interval on percentage of rooted lime stem cuttings………………………….……………………………… 66 4.4.1. Seasons……………………………………………………………………………… 66 4.4.2. Girdling…………………………………………..………………………………… 66 4.4.3. Sowing intervals…………………………………………………………………